6V6 homebrew transmitter—sorry, old low-res photo

6v6 homebrew xmtr

I still use this transmitter today.  Works great, puts out a wonderful CW note, and is rock-solid with the right crystals.  Just a standard 6V6 oscillator—I don’t recall the plate voltage and current, but it’s whatever the donor unit was.  The “donor” was a 1950s Grommes Precision commercial power amplifier of all things.  I found it at some swap meet for a few bucks, and thought it was just too art-deco to not do something with it.

So I stripped all the amp parts out, leaving the rather robust power supply section intact, and built a simple 6V6 oscillator transmitter in the case, with a PI-tank output circuit for easy loading into a 50-ohm antenna system.

My favorite crystal is cut for 3.523 on the 80m CW band, but it doubles nicely up to 7.046 with very very little radiation on 80m  on the fundamental.  The only downside to that crystal is that 7.047 is where the W1AW CW practice QST broadcasts are, and just about EXACTLY where the other end will tune to me allowing for sidetone.  So when W1AW is on, that crystal is out.

But the upside is for whatever reason, that one crystal makes this transmitter put OUT a full 5.5 watts of RF—no other crystal I’ve tried goes that hot.  3-watts is the best on any of the other dozen or so fundamental frequency rocks I’ve tried.

I wish I still had that groovy J-38 key with green cable… .alas, it was lost in a fire in 1997.  I built the transmitter and took this low-res photo in 1996.

But I still use the transmitter from time to time today—still puts out a great signal.

Schematic below—not very good image though.  Google AI2G transmitter by WB7AWK

amateur radio station    W7UUU

Grid CN87rf


CQ Zone 3